This research program is directed toward obtaining a better understanding of the basic mechanisms of speech production. This is to be accomplished through direct studies of speech physiology and speech acoustics as they relate to human communication and by indirect methods of speech synthesis. The methods to be used for direct observation of speech production include cineradiography and cinefibroscopy. Measurements of air flow through the mouth and intraoral pressure will also be made. Digital computer methods will be utilized for both data analysis and model simulation. Data obtained in these investigations will be used for formulating models of the process involved. Computer simulated models will be used as a basis for testing the state of knowledge concerning certain aspects of speech production and, if found adequate, will provide synthesis procedures. These synthesis procedures will then provide working models of these aspects of speech production which can be used for further investigations into mechanisms of both normal and pathological speech production.